1. Field of the Invention
A system is disclosed for use with water circulating devices to enable recovery of heat from flue gases and the like. The system employs means for transferring heat from the flue gases to water and then circulating the heated water to storage means, such as a water tank, for subsequent use. Sensing means are included for use in the flue-stack and in the water tank to provide signals, when temperatures are suitable in the flue-stack and the tank, which control pump means to divert the flow of heated water to the storage tank and cold water from the storage tank.
2. Description of the Prior Art
The prior art systems for transferring heat from one medium to another include heat exchangers making use of a number of pipes in a shell. Such heat exchangers are too cumbersome and too expensive for use in many systems for which the present invention, employing heat pipes, is suited. Other systems are know in the prior art which make use of heat pipes. These generally have been limited to the transfer of heat from a hot gas source to a cooler gas. These latter systems have the characteristic disadvantage that the heat must immediately be utilized, since there is no way available to economically store the heat in the gas for use at a later time. The transfer of heat from gases to water via heat pipes also is known from the literature. However, none of the known systems have employed circulating means controlled in accordance with measurements of temperature of the flue gases and the temperature of water in a storage tank. Furthermore, none of the known systems have suggested combining the sensing and circulating means with the storage of heat. Consequently, these earlier systems have not been useful except where the heat representing salvaged energy can be immediately used.